Axle play

matthewheld · **Posted:** Thu Jan 31, 2008 3:19 pm

I finished installing my Powertrax traction system (not the Lock Right) into the rear differential. When I had both axles pulled partially out for installation, I noticed quite a bit of play in the axle. I could move the axle up/down about 1/8 inch, even after final installation.
I've heard stories of Powertrax grenading in the differential, and I'm concerned about the axle play. Anyone else have this problem?

As a side note - the Powertrax gives me reason for concern, just because of its configuration. It does not reassure me that those outer springs are held in by a small inner spring sitting in a groove.

Straight6Jeff · **Posted:** Thu Jan 31, 2008 3:39 pm

When you say the axle has 1/8 play, what exactly are you referring to? is is play at the brake side up/down...which would be outer axle bearings. Is it in/out play of the entire shaft..which is normal. I hve built and rebuilt hundreds of diffs, rears and fronts on many different vehicles, so I am familiar with the different movements.

As a side note, I am not a fan of the powertrax or any other lunchbox type locker. However, the tolerances on the 8.25 (or any diff for that matter) are not the most exacting when they are machined at the factories. So, Even if the powertrax is perfectly machined to 0.0001 tolerance, the carrier housing will vary from one vehicle to the next. A very loose or very tight carrier will affect the way any lunchbox type locker performs and it's subsequent durability.

Jeepjeepster · **Posted:** Thu Jan 31, 2008 3:55 pm

Im not much on the power-trax either. Ill be taking mine out this spring.

matthewheld · **Posted:** Thu Jan 31, 2008 4:08 pm

Straight6Jeff wrote:

When you say the axle has 1/8 play, what exactly are you referring to? is is play at the brake side up/down...which would be outer axle bearings. Is it in/out play of the entire shaft..which is normal. I hve built and rebuilt hundreds of diffs, rears and fronts on many different vehicles, so I am familiar with the different movements.

As a side note, I am not a fan of the powertrax or any other lunchbox type locker. However, the tolerances on the 8.25 (or any diff for that matter) are not the most exacting when they are machined at the factories. So, Even if the powertrax is perfectly machined to 0.0001 tolerance, the carrier housing will vary from one vehicle to the next. A very loose or very tight carrier will affect the way any lunchbox type locker performs and it's subsequent durability.

With the wheel and brake caliper off, I can grab the axle hub and move it laterally 1/8 inch. I'm not talking about pulling/pushing the axle in and out of the housing, but side to side, up and down movement. So yes, it would be the outer axle bearings.

Straight6Jeff · **Posted:** Thu Jan 31, 2008 4:21 pm

There will be some movement. If the there is not any brinnelling on the bearing faces, axle (where the bearing rides), if there is not any fluid leakage, and you don't have any whining or unusual noises from the rear, just run it. Mine has about 1/16 movement. It has had that much since day two of ownership (bought new). New bearings are not difficult to do if you already have the axles out.

How many miles are on it?

My Dad's 02 libby has a light 1/8 movement and it has been fine for 40k miles.

matthewheld · **Posted:** Thu Jan 31, 2008 4:31 pm

Straight6Jeff wrote:

There will be some movement. If the there is not any brinnelling on the bearing faces, axle (where the bearing rides), if there is not any fluid leakage, and you don't have any whining or unusual noises from the rear, just run it. Mine has about 1/16 movement. It has had that much since day two of ownership (bought new). New bearings are not difficult to do if you already have the axles out.

How many miles are on it?

My Dad's 02 libby has a light 1/8 movement and it has been fine for 40k miles.

I have 94,000 miles on it. The inner bearings/seals were just replaced, but I never addressed the outer bearings.

matthewheld · **Posted:** Thu Jan 31, 2008 4:56 pm

Straight6Jeff wrote:

I hve built and rebuilt hundreds of diffs, rears and fronts on many different vehicles, so I am familiar with the different movements.

Straight6Jeff,

I keep thinking that I should have replaced the outer bearings when I installed the Powertrax. I've always done my own auto work/maintenance, but never had to work on a rear end. How hard is it to replace the bearings, besides the fact that I have to disassemble the Powertrax and remove the axles. Do you need a puller of some kind?

tommudd · **Posted:** Thu Jan 31, 2008 5:56 pm

just a bearing puller, pull the axles (which you know how to do) and pop them out

Straight6Jeff · **Posted:** Fri Feb 01, 2008 8:58 am

Very easy to replace the outer bearings. Like Tommudd said, a bearing puller is all that is really needed. Just make sure you have a set of large sockets so you can use a socket to drive the new bearings into place. Make sure the socket does not touch the rollers in any fashion while driving in the bearing. If you have a seal driver, that makes setting the seal go a few seconds quicker. It is advisable to pick up a spare bearing and spare seal just in case one gets tweaked during install. Then return them if you do not use them. It will save a trip to the parts store. Just make sure the inner race (the axle shaft) is in good shape. If it has any heat marks, scores, pitting, etc., replace the shafts. The Yukon shafts can be found for a few bucks over a C-note (each). The yukons are a worth while investment if you have to replace the shafts. The shafts from the dealer will be way more expensive, and not nearly as high quality as the Yukon.

LostRenegade · **Posted:** Sat Feb 02, 2008 2:48 pm

matthewheld wrote:

I've heard stories of Powertrax grenading in the differential, and I'm concerned about the axle play. Anyone else have this problem?

I had the Powertrax gernade on me. It is not a pretty site when it happens. I had to replace my rear axel with a salvaged one.

My Powertrax was great while it lasted. The past few months before it blew, it wouldn't unlock. Which made it diffiuclt to make tite turns. It would drag a tire while turning. I let it go a bit to long and it broke.

matthewheld · **Posted:** Sun Feb 03, 2008 1:46 am

I'm going to replace the outer bearing at the next gear oil change. That'll give me an excuse to examine the Powertrax with 12,000 miles on it.

LostRenegade - how long (time & mileage) did you have the Powertrax before it grenaded?

LostRenegade · **Posted:** Sun Feb 03, 2008 4:52 pm

matthewheld wrote:

LostRenegade - how long (time & mileage) did you have the Powertrax before it grenaded?

About 60,000. I wheeled it really hard and noticed it no unlocking properly afterwards. I had some lower back problems so I didn't feel like crawling underneath to check it out. After a few months it broke...

When I replaced the axel I had them install a Detroit Locker. Much, Much better than the Powertrax.

Jeepjeepster · **Posted:** Sun Feb 03, 2008 8:29 pm

ohh wow, 60k is a pretty good lot.

Mine had around 10k(or thats what I was told) when I got it and Ive put 10k on it but Im still not happy with it.

I just dont like the fact that 100% of the torque goes to one wheel when its unlocked. Im not saying that it should stay locked more often, just that its not for me since I dont offroad that much. A LS would be better suited for me.

Axle play

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